Air cargo container with damage resistant base

ABSTRACT

An improved air cargo container has a base sheet attached to a base, and an enclosure which overhangs the back end of the base. Spaced apart lateral base supports are attached to the base sheet adjacent to a back end of the base sheet. The lateral base supports are parallel to each other and are also parallel to left and right sides of the base. Longitudinal base supports may be attached to the rear corners of the base sheet. The base supports provide additional stiffness to the base sheet in the highly stressed areas. The air cargo container is better designed to resist service damage.

BACKGROUND OF THE INVENTION

Air cargo containers have been used for the transportation of cargo by aircraft for many years. Cargo such as cartons, smaller shipping containers, etc. is first loaded into containers. The containers are then loaded into an aircraft. Use of air cargo containers is much faster than loading cargo directly into the cargo space of the aircraft, since the individual cartons need not be separately placed and secured within the aircraft. The air cargo containers can also be loaded at locations remote from the airport. Furthermore, because the cargo containers are typically designed and constructed to correspond to the interior dimensions of the aircraft cargo space, the containers fit more securely in the cargo space and do not shift during flight, as they are also locked to the floor. These and other advantages of air cargo containers have made air cargo containers widely used in the air freight industry.

As with most equipment used on aircraft, two primary design goals for air cargo containers are that they be both lightweight and capable of restraining cargo during FAA stipulated crash conditions. As shown in FIGS. 1 and 2, a typical air cargo container 10 includes a base 14, which is typically a flat rectangular aluminum pallet. A frame 12 is attached to the base, with the frame generally having a back wall, a front wall, left and right side walls and a top. In many air cargo containers, a lower section 16 of the back wall extends at an angle to the base 14. For example, in the air cargo container 10 shown in FIGS. 1 and 2, a wall 16 extends at an angle from angle gusset 15 at the back wall of the container to base 14 of the container. This allows the container 10 to better fit within the curved fuselage of the aircraft. However, it also tends to result in uneven loading on the base 14. Specifically, the area of the base adjacent to the angled lower section, referred to here as the stress area 18, is subjected to higher bending moments than the rest of the base, when the container 10 is conveyed over uneven conveying surfaces, for example uneven rollers. This results in service damage at the stress area 18, which generally extends about 12-18 inches forward from the back wall of the container.

This problem of service damage to the uneven loading characteristics of the air cargo container 10 has long presented engineering challenges. One proposed solution is the use of a doubler plate 22, as shown in FIG. 3. In this design, a doubler plate 22 is riveted onto the base plate 17 of the base 15. Typically the doubler plate is a rectangular plate having a width of about 12-15 inches, and a length selected to extend completely from the left side wall to the right side wall of the container 10 (generally about 60 inches). Commonly, the base plate 17 and the doubler plate 22 are about 0.10 to about 0.12 inches thick. Although the doubler plate 22 significantly decreases in service damage, it also adds up to 15 pounds to the weight of the container (depending on the specific container size).

An alternative design proposed to reduce in service damage to the stress area 18 is shown in FIG. 4. In this alternative design, spaced apart hat section strips or pieces 24 are attached onto the base plate 17 with rivets 26. While this design is much lighter than doubler plate design shown in FIG. 3, it has proven to be incapable of making any real reduction to in service damage of the stress area 18.

Accordingly, improved air cargo containers that are more resistant to in service damage are needed.

SUMMARY OF THE INVENTION

An improved air cargo container has now been invented which is highly resistant to service damage, and is also lightweight. In one aspect, this new air cargo container includes a base sheet attached to a base, and an enclosure which overhangs the back end of the base. Spaced apart lateral base supports are attached to the base sheet adjacent to a back end of the base sheet. The lateral base supports are parallel to each other and are also parallel to left and right sides of the base. The lateral base supports may be provided as a metal extrusion having a central top channel in a top surface of the extrusion and first and second bottom channels on a bottom surface of the extrusion, and with the first and second bottom channels on opposite sides of the central top channel. The lateral base supports provide additional stiffness to the base sheet in the highly stressed areas of the base sheet. The air cargo container is better designed to resist service damage.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the same element number indicates the same element in each of the views.

FIG. 1 is a side view of a prior art air cargo container.

FIG. 2 is a front view of the air cargo container shown in FIG. 1.

FIG. 3 is an enlarged section view detail of a prior art air cargo container.

FIG. 4 is a section view of the base of another prior art air cargo container.

FIG. 5 is a section view of a base sheet support.

FIG. 6 is a top view of a base of a new air cargo container using the base sheet support shown in FIG. 5.

FIG. 7 is an enlarged section view detail of an end of a base sheet support shown in FIG. 5.

FIG. 8 is a top view of a base of an alternative embodiment of a new air cargo container using the base sheet support shown in FIG. 5.

FIG. 9 is a top view of a base of another alternative embodiment of a new air cargo container using the base sheet support shown in FIG. 5.

FIG. 10 is a section view taken along line 10-10 of FIG. 9.

DETAILED DESCRIPTION OF THE DRAWINGS

An improved air cargo container having better resistance to in service damage has now been invented. This new air cargo container is strengthened in the stress area 18, and better resists bending loads resulting from uneven loading. As shown in FIG. 6, the new air cargo container has a frame 12 and a base 14 which may be similar to or the same as the prior art air cargo container shown in FIGS. 1 and 2. However, the new air cargo container 50 has spaced apart lateral base supports 52 extending inwardly across the stress area 18 from the adjacent to the back wall of the air cargo container. In the example shown in FIG. 6, the lateral base supports 52 are equally spaced apart on 2.6 inch centers. This spacing may range from about 1.5 to 4.0 inches for most designs. The lateral base supports 52 are parallel to each other, and to the left and right side walls of the container 50. The lateral base supports 52 in FIG. 6 all have the same length, which generally is about 12-20 or 15-18 inches. The lateral base supports 52 are attached to the base plate 17 via rivets 26 or other fasteners, adhesives, or welding. In the example shown in FIG. 6, five equally spaced apart rivets 26 are used to attach each of the 13 lateral base supports 52 onto the base plate 17.

The lateral base supports 52 significantly increase the bending modulus of the stress area 18 of the base 14 of the air cargo container 50, in comparison to the designs shown in FIGS. 3 and 4. Specifically the lateral base supports 58 resist bending or sagging of the back edge of the container.

FIG. 5 shows a sample cross section of the lateral base support 52. In this example, the dimensions in inches are: AA=1.0; BB=0.4; CC=0.3; DD=0.24 and EE=0.12. The lateral base supports 58 may be aluminum 7075T6. The lateral base support 58 may have top channel 32 to allow the rivets to be recessed within the support 52. Bottom channels 34 may also be included to reduce weight with minimal reduction in bending modulus.

Referring once again to FIG. 6, uneven loading on the base 14 also causes the left and right sides at the back of the base to bend or sag under load, essentially creating a longitudinal stress area 20. The longitudinal stress area 20 is located at sides of the base, and of course overlaps with the lateral stress area 18, as loading at the back corners of the base causes deflection along both axes (i.e., along the back edge and also along the sides of the base). For this reason, longitudinal base supports 54 may be provided at the sides of the base.

The longitudinal base supports 54, as shown in FIG. 6 extend inwardly from the left and right edges of the base 14, and are perpendicular to the lateral base supports 52. In the design shown, five longitudinal base supports 54 are provided on each side. The longitudinal base supports 54 may be the same material and design as the lateral base supports 52, as described above. As shown in FIG. 7, the front ends 66 of the lateral base supports 52 may be slanted or angled, to allow cargo to more easily slide up and over the base supports 52.

FIG. 8 shows an alternative air cargo container 60 which may be the same as the air cargo container 50 shown in FIG. 6, except that no longitudinal base supports 54 are used. Lateral base supports 52 are attached to the base sheet 17 across the entire width of the base 14. The lateral base supports 52 at the sides of the container, and at the center of the container, may optionally be longer than the other lateral base supports 52. As shown in FIG. 8, the lateral base supports 52 at the sides and center of the base 14 are 10-30% longer than the other lateral base supports.

FIG. 9 shows another alternative air cargo container 70 which is also similar to the air cargo container 50 shown in FIG. 6, but also having full width supports. A first full width support 72 extends across the base sheet 17 in front of the forward ends of the lateral base supports 52. The full width support 72 may have the same cross section as the lateral base supports 52, which is shown in FIG. 5. A second full width support 74 is spaced 2-8 inches in front of the first full width support 72. The second full width support 74 may have a cross section similar to the supports 52 and 72, but with an angled side, to help cargo slide up and over the support 74.

Thus, novel air cargo containers have been shown and described. Various changes and substitutions may of course be made without departing from the spirit and scope of the invention. The invention, therefore, should not be limited, except by the following claims and their equivalents. 

1. An air cargo container comprising: a base including a base sheet; left and right sidewalls attached to the base, and a back wall having a lower section and an upper section, with the lower section attached to the base and extending upward at an angle to the base; and a plurality of spaced apart lateral base supports attached to the base sheet adjacent to a back edge of the base sheet, with the lateral base supports parallel to each other, parallel to left and right sidewalls, and perpendicular to the back edge of the base sheet.
 2. The air cargo container of claim 1 with the lateral base supports comprising a metal extrusion having a central top channel in a top surface of the extrusion and first and second bottom channels on a bottom surface of the extrusion, and with the first and second bottom channels on opposite sides of the central top channel.
 3. The air cargo container of claim 1 with the extrusion having width of 0.75 to 2.00 inches and a height of 0.18 to 0.37 inches.
 4. The air cargo container of claim 1 further comprising a first set of longitudinal base supports attached to a back left corner of the base sheet, and a second set of longitudinal base supports attached to a back right corner of the base sheet, with the longitudinal base supports perpendicular to the lateral base supports.
 5. The air cargo container of claim 4 wherein the longitudinal base supports are shorter than the lateral base supports.
 6. The air cargo container of claim 4 wherein all of the lateral base supports are positioned in between the first and second sets of longitudinal base supports.
 7. The air cargo container of claim 2 with the longitudinal base supports also comprising the extrusion.
 8. The air cargo container of claim 1 with the lateral base supports extending forwardly by 10-20 inches substantially from a rear edge of the base sheet.
 9. The air cargo container of claim 1 with one or more of lateral base supports having an angled front end.
 10. The air cargo container of claim 1 with a first set of the lateral base supports having a first length and a second set of the lateral base supports having a second length different from the first length.
 11. An air cargo container comprising: a base including a base sheet; a back wall having a lower section oriented at an acute angle to the base; a plurality of spaced apart lateral base supports attached to the base sheet adjacent to a back end of the base sheet, with the lateral base supports parallel to each other.
 12. An air cargo container comprising: a base including a base sheet; a back wall having a lower section oriented at an acute angle to the base; a plurality of spaced apart lateral base supports attached to the base sheet adjacent to a back end of the base sheet, with the lateral base supports parallel to each other; a first set of longitudinal base supports attached to a back left corner of the base sheet, and a second set of longitudinal base supports attached to a back right corner of the base sheet, with the longitudinal base supports perpendicular to the lateral base supports, and with the lateral base supports in between the first and second sets of longitudinal base supports; and at least one full width support attached to the base sheet in front of substantially all of the lateral base supports, and oriented perpendicular to the lateral base supports.
 13. The air cargo container of claim 12 with the at least one full width support extending from a left side to a right side of the base sheet.
 14. The air cargo container of claim 12 further comprising a second full width support attached to the base sheet in front of the first full width support, with the second full width support having an angled front surface.
 15. The air cargo container of claim 12 wherein the base sheet has a front to back dimension DD, and all of the supports are located within 0.4 DD from the back end of the base sheet. 